145821 has 8 divisors (see below), whose sum is σ = 209440. Its totient is φ = 89712.

The previous prime is 145819. The next prime is 145823. The reversal of 145821 is 128541.

It is an interprime number because it is at equal distance from previous prime (145819) and next prime (145823).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 145821 - 2¹ = 145819 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145823) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1831 + ... + 1908.

It is an arithmetic number, because the mean of its divisors is an integer number (26180).

2¹⁴⁵⁸²¹ is an apocalyptic number.

It is an amenable number.

145821 is a deficient number, since it is larger than the sum of its proper divisors (63619).

145821 is a wasteful number, since it uses less digits than its factorization.

145821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3755.

The product of its digits is 320, while the sum is 21.

The square root of 145821 is about 381.8651594477. The cubic root of 145821 is about 52.6348460954.

The spelling of 145821 in words is "one hundred forty-five thousand, eight hundred twenty-one".